1. Field of the Invention
The apparatus of the present embodiment of the invention relates to syringes. More particularly, the apparatus of the present embodiment of the invention relates to syringes having a body entering conduit which is retractable prior to or after injection, having a piston movable reciprocally and axially within a cylinder portion, having a piston locking device and a cap device providing protection for the aperture for the body entering conduit following retraction.
2. Prior Art
Syringes are used for the injection or removal of fluent material for a variety of necessary medical procedures. However, after the injection procedure is completed, problems may arise as a consequence of contamination of the needles. By way of example, the syringe may be used to treat a patient having a communicable disease. Due to improper disposal of these syringes and/or through general use or misuse of them, health care workers themselves have been infected with the diseases they have attempted to treat, such as AIDS, due to accidental needle strikes. Also, by way of example, drug users have been able to obtain previously used and infected syringes. It is known that such syringes have been used in an illicit capacity thereby furthering the spread of contagious diseases.
The following U.S. Pat. No. provide examples of syringes having a needle which may be retracted into the syringe cylinder after use:
U.S. Pat. No. 4,804,370; Feb. 14, 1989 PA1 U.S. Pat. No. 4,826,484; May 2, 1989 PA1 U.S. Pat. No. 4,826,489; May 2, 1989 PA1 U.S. Pat. No. 4,836,373; Jun. 6, 1989
Whatever the precise merits, features and advantages of the above cited references, none of them have the means by which the needle may be retracted within and shielded by the syringe cylinder by means of a hooking device, a piston locking device and cylinder capping device as hereinafter described so as to lessen the number of accidental needle strikes and the possible spread of disease. Moreover, with respect to the capping device, little is available providing free standing, finger protecting syringe cylinder aperture covering following needle retraction.